Let-off mechanism for looms



LET-OFF MECHANISM FOR LOOMS APPLICATION FILED FEB. 18, 1919.

. 1 ,330,255, Patented Feb. 10,1920.

. Fig.4. 8

L 1 inventor.

7 Ernest A.Gc1gnon I by MJMQFM Atty s.

UNITED srarns PATENT onnron.

ERNEST A. eaenon, or SALEM, MASSACHUSETTS, AssIeNoa TO DRAPER coaronarron, or Hornnnnn, ara-ssacnnsnrrs, A CORPORATION OFMAINE.

LET-OFF MECHANISM FOR LOOMS. I

Application filed February 18, 1919. Serial No. 277,736.

To all whom it may concern:

Be it known that I, ERNEST A. GAGN N, a subject of the King of Great Britain, and resident of Salem, county of Essex, State vof Massachusetts, have invented; an Improvement in Let-Ofl vMechanisms for Looms, of which the following description, in connection with the accompanying drawing, is a specification, like characters on' the drawing representing like parts.

This invention relates to improvements in let-off mechanisms for .looms and the object. thereof is to provide an improved connection between certain of the instrumentalities of the let-01f controlling mechanism. More specifically the present invention comprises certain improvements in the 'letoff mechanisms of the well known Draper- Roper type, which is exemplified in Patents lay, the amplitude of the oscillation of said pawl being controlled in part by arocker, one arm of which engages the mass of yarn uponthe warp beam and the other arm of which operates a bar which governs the effective radius of the pawl carrier. This bar, which may be called a radius bar, in commercial machines of this type comprises a substantially vertically disposed link which is connected at its lower end to that one of the arms of the rocker which is controlled by the diameter of the massof warp upon the warp beam.

The upper end ofthe radius bar 1s providedwith studs which extend into slots 1n the cooperating members of a compound I pawl carrier the oscillation of which rotates a ratchet which in turn actuates the mechanism for rotating the warp beam. This radius bar being thusvfreely supported at its lower end has heretofore beencapable of more or less lateral movement and has customarily been secured upon the pivotal stud by which it is connected to the rocker arm bv a cotter pin or other suitable locking devlce.

If the cotter pin or locking device hecomes broken or is accidentally omitted in assembling the machine the radius bar is likely to becomedisengaged from its supvention as applied thereto,

porting and actuating arm and drop down, thereby causlnga defect 'in the weave.

The present lnvention contemplates the Specification of Letters Patent. Pat t d F b lo 1920 provision of a connection between the radius bar and the arm whichactuates it which cannot be disengaged during the operation of theloom. This is accomplishedin the preferredembodiment of the invention disclosed hereinby offsetting the arm Which leads from the rock shaft of the controlling device to'the radius bar so that the end of the'arm which engages the radius bar will be positioned between the loom'side and the radius bar and the stud upon which the lower end oftheradius bar is mounted will projec away from the loom side through the journal in the radius bar a sufiicient distance toprevent the disengagement by reason of anylateral movement of which the loosely supported radius bar mayfbe capable.

The drawings illustrate a preferred embodiment of my invention in which,

Figure 1 is a side elevation of a portion'of a loom illustrating a suflicient portion of the usual let-off mechanism to disclose my}in-' Fig. :2 is a view partly. in section illustrating the radius bar, its connection to the compound pawl carrier and the improved connection between the lower end ofjsaid radius bar and thecontrolling rock shaft,

Fig. 8 is a side elevation of the improved arm which connects the. radius bar to its actuat ng rock shaft, and,

Fig. 4 is a plan view of, the same.

In the, usual type ofvDraper-R oper let-elf mechanism to whichvthe presentglinvention is applied, as illustrated in the accompanying drawing, the warp-, bea m"1'i's suitably.

which is itself rotatedby mechanism'includ mg a circular ratchet 4 and a cooperating pawl 5 carried by a member 6 of a compound pawl carrier which is oscillated from' the rock shaft which supports the lay. cf the loom.

Y V In order to produce an even weave means means being actuated by the tensionfofjthe 95 mounted in the loom sides 2and is rotated' through a tram offgearingffronrashaft?) warp as it runs over the whip roll while the other portion comprises means for varying the amplitudeof oscillation of the pawl 5 as the diameter of the yarn mass upon the warp beam decreases. The general mechanism for accomplishing this purpose may be and is similar to that disclosed in the patents above mentioned in which the member 6 of the compound pawl carrier is in the form of an arm having ribs spaced apart to form a slot 7 and provided with a hub 8 which is rotatably mounted upon the shaft 3. An arm 9 extending downwardly from the hub 3 and integrally therewith is connected to a rod 10 which is provided at its opposite end with a slot engaging a stud upon an arm (not shown) rigidly connected to the rock shaft which carries the lay so that the oscillation of the lay rock-shaft will impart through the rod 10 an oscillation to the member 6,of the compound pawl carrier. The other member of the compound pawl carrier comprises an arm 11 which is pivotally mounted on the loom side and provided with a slot 12 complementary to theslot 7 of the member 6. The member 11 of the compound pawl carrier is controlled by mechanism which is actuated by the variation in tension upon the warp as the cloth is being woven, an increase in tension serving to rock the member 11 of the compound pawl carrier in such a manner as to increase the amplitude of movement of the pawl as is clearly setforth in the patents above mentioned.

In order to provide for a uniform rate of delivery of warp as the diameter of the warp mass upon the warp beam decreases, mechanism is provided for automatically varying the effective radius of the compound pawl carrier. This mechanism comprises a' radius bar 13 having upon its upper end laterally extending bosses or studs 14, 15 which enter respectively the slots 7 and 12 of the members 6 and 11 of the compound pawl carrier. At its lower end the radius bar 13 is connected to an arm 16 which is secured to a rock shaft 17 mounted in the sleeve 18 carried by the loom side, the other end of said rock shaft being connected to an arm 19 which is provided at its upper end with an enlarged portion or roller adapted to rest upon the mass of warp upon the warp beam. 7

As the diameter of the mass of warp upon the warp beam decreases, the arm 19 propressively approaches the shaft of the warp beam thereby rocking the shaft 17 and depressing the arm 16, thus gradually lowering the radius bar 13 and its pivotal connection between the oscillating members of the compound pawl carrier.

As the radius bar is thus lowered the effective length of the member 11 of the compound pawl'carrier which is controlled from the whip roll is increased. Thus the action of the Whip roll causes a greater movement of the member 6 of the compound pawl carrier as the diameter of the warp beam decreases, so that the pawl 5 passes over a greater number of teeth upon the ratchet a and causes an increased rotation of the warp beam.

In commercial machines heretofore manufactured the arm 16 has extended directly at right angles from the shaft 17 and has been provided with a stud extending through the radius bar, toward the loom side. By reason of the fact that the radius bar was loosely supported it was necessary to place a cotter pin or other locking means in the end of the stud to prevent the radius bar from slipping off of the stud, thereby improperly varying the throw of the pawl 5 and causing a defect in the weave of the cloth.

The present invention is designed to provide a positive connection between the radius bar and the arm which actuates it which cannot become disengaged and which will not require the use of a cotter pin or other lockin device. This is accomplished in the present invention by forming the arm 16 with an offset portion 20 which extends parallel with and in proximity with the loom side 2, the outer end of said arm being provided with a stud 21 projecting away from the loom side and of such length as to extend a considerable distance through the bearing 22 in the lower end of the radius bar 13. 7

By reason of the fact that the offset portion 20 of the arm 16 lies between the radius bar and the loom side the radius bar cannot slip off of its pivotal support as was possible in former constructions and by providing a stud of'suflicient length it is prevented from slipping. The position of other usual parts of the warp beam actuating mechanism and the engagement of the ends of the studs 14, 15 with the bottom of the slots 7 and 11 respectively will prevent said radius rod from slipping olfin the other direction,

It will be understood that various changes in form and construction may be made within the spirit and scope of the following claim.

Having thus described my invention what I claim as new and desire .to secure by Let ters Patent is:

In a loom comprising loom sides, a warp beam journaled therein, means for rotating said warp beam including a circular ratchet and a cooperating pawl, a compound pawl carrier for said pawl, means for oscillating said pawl carrier, means for controlling said pawl carrier'including mechanism operated by the tension of the warp upon the whip roll for varying the extent of movement of said pawl, a radius bar having means engaging said compound pawl carrier and adjustable relatively thereto to Vary the throw of said pawl, a radius bar controlling device including a rocker having means engaging the mass of yarn upon the warp beam and an arm connected to said radius bar, said arm being offset to lie between theloom side and said radius bar and having'a" long stud pronisms to confine the radius bar against disi placement and disengagement from said 1 stud.

In testimony whereof, I have signed my name to this specification.

ERNEST A. GAGNOVN," 

